BRPI0619002B1 - THREADED PIPE JOINT FACTORY SURFACE - Google Patents

Abstract

threaded pipe joint. a threaded metal gasket has the pin (100) and housing (200) thread surfaces covered with a liner comprising a first layer (24) disposed on the overall surface of the pin element (100), and a second layer (25). ) arranged in part on the surfaces of any of the pin or housing elements. In a first aspect, the coating comprises a first layer with high friction coefficient and anti-seizing properties, disposed on the entire surface of the pin element (100), and a second layer (25) with low friction coefficient properties, disposed on specific parts of the surfaces of any of the pin or box elements. preferably, the specific surfaces are those which are in reciprocal radial contact during constitution until the pin and housing reach the point at which the shoulders (9, 10) are in contact with each other. The second layer may contain polytetrafluoroethylene (ptfe). In a second aspect, the first layer with high friction coefficient and anti-seizing properties is arranged on the entire surface of the housing element (200).

Description

THREADED JOINT FOR PIPES WITH A SURFACE COATING

TECHNICAL FIELD [0001]

The present invention relates to a threaded joint particularly adapted for pipe segment connections, for the production of strands used in the oil and gas extraction industry, provided with a surface coating covering the thread to enhance the resistance of the joint to torsion.

FUNDAMENTALS

THE INVENTION

0002]

In prospecting and extracting oil, it is common practice to use metal tubes of a commercial length, which are formed to form a cord long enough to reach the depths in which the oil or gas reservoirs or reservoirs are located. The depth of the reservoirs is constantly increasing and, therefore, the joints have to be designed in such a way that they can withstand higher loads and stresses, while ensuring good sealing properties.

[0003]

An improvement in the performance of threaded joints is achieved by an adequate design of all the load-bearing surfaces of the pin and housing, that is, threaded flanks, strut shoulders, etc., to make them maintain reciprocal contact with structural interference. and dimensional in all load ranges, where joints are expected to operate. This depends on the torque intensity that can be applied, where the torque intensity is determined by the difference between the plastic flow torque value and the rebound torque value.

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2/21 [0004] However, the provision of a very high one causes an interference, which is harmful to the constitution operation, since this can cause the joint to become stuck or bruised. Efforts have been made to achieve a good balance between having a low torque of constitution and having a high torque of plastic flow, which is a condition to withstand high loads and to have good sealing properties.

[0005] On the one hand, to avoid jamming during construction, the state of the art technology generally uses a fluid lubricant, for example, grease or grease.

[0006] Efforts are also being made to increase the limit of plastic flow torque, which has always been an important aspect for research in this technical field. The plastic flow torque (Y.T.) was generally increased by modifying the joint design, but came close to the technical limit for lubricated joints.

[0007] The use of grease has disadvantages and will preferably be avoided. The risks imposed by the use of grease include: dirt retention; non-uniform distribution of grease, depending on manual operation, which can also cause over-lubrication in all or part of the joint; and cleaning the

together has to be conducted at the oil field, in conditions adverse environmental effects. [0008] Therefore, to reduce the costs and perfect at operations, solutions without using grease for at

together they were developed and have been used for several years. At

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3/21 solutions without the use of grease obtained a good resistance to torsion, but, in some cases, they have disadvantages because the constitution torque can reach high values. In such cases, the torque for the constitution of solutions without the use of grease for joints is usually reduced by the addition of oils or contaminants, thereby losing partially or totally the advantages of solutions without the use of grease and generating the risk of reducing also the torque value of the plastic flow and the super torque of the joint.

[0009] Grease-free solutions for joints have been described in several patents, for example, U.S. patents 4,414,247, 6,027,145 and 4,692,988. They use a unique anti-sealing coating instead of grease with the same friction factor at all points on the joint surface. An appropriate friction value must also be selected for these joints, because an increase in the friction factor, to accentuate the value of the plastic flow torque also increases the rebound torque, while a reduction in the friction factor makes it possible to conduct the constitution with cam torque values similar to those of joints

known lubricants, but it reduces its value in torque in plastic flow. At consequences on both the cases are that the torque value is low and unsatisfactory. SUMMARY OF THE INVENTION [0010] The main object of this invention is to eliminate at

deficiencies mentioned above by means of a threaded joint for tubes, with excellent properties of constitution and still obtain high structural performances, for providing a torque with a very high value. It is also another object of

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4/21 invention provides a threaded joint, which also has a good corrosion resistance value within a wide range of environmental and operational conditions, guaranteeing optimum performance, even after several joint constitution and disintegration operations.

[0011] The objects mentioned above and others that will become evident in view of the description presented below, are achieved according to the present invention by means of a threaded joint for tubes, comprising a pin element and a box element, the pin element having a thread adapted to fit a thread of the box element, a thread shape of each of the pin element and box element being defined by a thread profile that is arranged in a cross section containing a longitudinal axis (X) of the gasket, where the surface of the thread is provided with a coating, wherein said gasket comprises a first layer disposed on the entire surface of the pin element, a second layer disposed on specific parts of all surfaces of any of the pin elements or box, or the coating comprises a first layer disposed on the total surface of the box element, a second layer disposed on specific parts of all surfaces of q u any of the pin or box elements.

[0012] In a first aspect, the coating comprises a first layer with high friction and anti-sticking properties, arranged over the entire surface of the pin or box elements, a second layer with low friction properties disposed in specific parts of all surfaces. any of the pin or box elements.

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5/21 [0013] Preferably, the overall surfaces of any of the pin or box elements, in which a second layer with low friction properties in specific parts, are those adapted for the production of reciprocal radial contact.

[0014] Particularly, the parts of the surface of any of the pin or box elements, in which a second layer with low friction properties are arranged, are those adapted to produce reciprocal radial contact, during constitution, until a surface undergoing a axial contact pressure load contact (such as the shoulders).

[0015] Particularly, the parts adapted for the production of reciprocal radial contact are crests in the box element, roots in the pin element and metal - metal seals.

[0016] The main advantages of the joint of the invention are presented below.

[0017] Allows the achievement of resistance to higher torsion, due to the dry anti-sealing coating, having different friction coefficients in different areas of the joint.

[0018] It has, therefore, a low rebound torque and a high plastic flow torque, increasing the permissible torque value, providing an improvement of resistance to

twist, without changing the geometry gives together and without increase the value of constitution torque. [0019] Overcomes disability of together of state of technical, that cannot have areas located in high friction,

because they use lubricants that flow in all spaces

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6/21 left empty between the threads and cover all areas of the joint.

[0020] When using grease in the joints, the friction factor obtained will usually depend on the amount of grease applied, as a pressure of grease normally builds up inside the joint, due to the small evacuation or compensation of the available space between the threads of the pin and the housing. Instead of the joint according to the invention, the friction factor is independent of the operator's influence and is determined at its production stage.

[0021] According to another important aspect of the invention, a low-friction coating is used in specific areas of the pin or box threads and metal-to-metal seals, with radial contact on the complementary surfaces of the pin or box, respectively, for ensure low values of torque for constitution, because these are the surfaces that are in contact during the screwing of the thread, in a condition devoid of load.

[0022] A high friction coating is used on those surfaces that promote axial contact, for example, the nose of the pin, the torque shoulder and the load flank of the thread, to provide greater resistance to torsion, because these surfaces suffer from axial contact pressure loads, when the pipe connection reaches the final position. By providing torque in a joint through the coating, the basic disadvantages of solutions without the use of grease are eliminated and an advantage over the lubricated joint is produced, because it allows separate and high precision control of two different parameters what

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7/21 are closely related to each other in the joints of the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS [0023] The present invention will be described below according to a preferred embodiment of it, which is presented by way of a non-limiting example, by means of the attached figures, in which:

[0024] Figures 1a and 1b show an enlarged sectional view of a detail of the thread in a joint according to the invention, in a first operational stage (during constitution);

[0025] Figures 2a and 2b show an enlarged sectional view of a detail of the thread in a joint according to the invention, in a second operational stage (when the connection reaches the final position);

[0026] Figures 3a and 3b show enlarged sectional details of the thread of a box and a pin, with a second layer on specific parts of an overall surface of a joint produced according to the invention;

[0027] Figure 4 shows comparative graphs relative to the values of the shoulder torque in joints, for all three types of coverings, for threaded joints;

[0028] Figure 5 shows an enlarged view of the surfaces of a pin and a box incorporated in a joint according to the invention;

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8/21 [0029] Figure 6 shows an enlarged view of the surfaces of a pin and a box incorporated in another embodiment of a joint according to the invention;

[0030] Figure 7A shows the friction coefficient measured over time for the three types of threaded joints discussed in Example 1;

[0031] the Figure 7B show the coefficient medium friction for the three types in together threads discussed in the Example 1; and [0032] the Figure 8 show the results testing

constitution and disaggregation, which were conducted in the three types of threaded joints discussed in Example 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION [0033] With particular reference to Figures 1 and 2, a tube according to the present invention has threaded ends which, when coupled with another tube having complementary threaded ends, form a joint. A joint thus comprises a tube defining a male element 100, the so-called pin, provided with a thread 4 on an external surface, and a female component 200, the so-called box, having a thread 3 on an internal surface. Box 200 is generally a tube or a sleeve, depending on the type of joint. The box 200 also has a contact shoulder 9 and the pin 100 has a corresponding shoulder 10. Figures 1a and 1b show the position of the pin and the box, before the constitution operation is completed, where the contacts 9 and 10 do not are still in contact. At this stage, which usually corresponds to the assembly of the tube string, the only charge

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9/21 important in the joint consists of the contact between the radial surfaces of the thread. The resulting stresses caused by the interference generated in the design stage are indicated schematically by the thick arrows 5 'and 5' '. The interference between the crests of the thread and the roots of the thread is not high enough to produce jamming during constitution, by using a suitable lubricant (grease or coating), but generating the arc tension in the components necessary to center the pin, during operation, perfecting the positioning of your nose.

[0034] Also in correspondence with the nose, radial interference is provided, for example, to create a metal-to-metal seal, which generates tensions, the consequence of which is shown schematically by the thick arrows 6 'and 6' '.

[0035] In Figures 2a and 2b, the same parts of the threads are shown as in Figures 1a and 1b, although in a completely screwed-on position. In these figures, the consequence of the contact pressure, produced by the torque on the flanks of threads 3 and 4, is represented schematically by the thick arrows 7 'and 7' ', while the consequence of the contact pressures produced by the torque on the contacts 9 and 10 is represented schematically by the thick arrows 8 'and 8' '. The 8 'and 8' 'are almost parallel to the longitudinal axis X - X of the joint shown in Figure 2.

[0036] The angle of inclination of the arrows 7 ', 7' 'with the axis

X - X obviously depends on the inclination of the flanks of the thread, while the angle of inclination of the arrows 5 ', 5' 'of the thread ridges depends on the selected thread design. The direction of the 6 ', 6' ', 8' and 8 '' arrows depends on the geometry of the

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10/21 nose. In the thread shown in the figures, the radial contact surfaces are almost perpendicular to the tube axis, with an angle in the range of 90 ° ± 10 °, while the surfaces of

axial contact stay The an angle with the tube axis X - X in the 0 ° to ± range 25 °. [0037] Still what at figures show a thread with a tooth trapezoidal, the section of tooth can have other ways , without

depart from the scope of the invention. An elongation of a thread 3 of box 200 is shown in Figure 3a, and an elongation of a contact or nose region of a pin 100 is shown in Figure 3b. A first layer 12 coating on the surface of the global surface and a second layer 13 coating are shown schematically in Figure 3b, for example, in this case, on the outer surface of pin 100. As shown in Figure 3a, the threaded portion of housing 200 corresponding to the pin 100 can have a first layer 12 'and a second layer 13' perfectly similar on the surface or it can be made without the protective layer or, alternatively the layer can be made with a different structure or materials. It is also possible to have only one coating on the surface of the pin and no coating on the surface of the housing.

[0038] The structure of the first layer 12 coating may be different, depending on the parts of the joint in which it is arranged. The difference in the friction or tribology properties of the coating allows manipulation and obtaining different characteristics in the behavior of the thread, during constitution, controlling the necessary torque during the operation.

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11/21 [0039] According to a first aspect of the embodiments of the invention, an anti-sticking coating with a high coefficient of friction, generally shown as 12 or 12 ', is deposited on the entire surface of the pin and / or box elements, while an anti-sticking coating with a low friction coefficient, generally shown as 13 or 13 ', is deposited in areas with radial contact, usually thread ridges 14, lead flanks 14' and / or roots 14 ''. Preferably, the threaded loading flanks 15, at the contact shoulder and in the nose area 19, the high friction coefficient 12 or 12 'anti-jam coating remains as the only layer.

[0040] Alternatively, a high coefficient of friction anti-jam coating can be used to reduce the friction factor at the crest of the thread and / or root.

[0041] Due to the different friction factors, this peculiar distribution produces a difference between the contact surfaces of the pin and the box, when an arc interference is generated during the constitution, and the surfaces, which may be in contact increase the normal forces, since the nose of pin 19 reaches the back contact of the box.

[0042] The various alternatives of structure and materials constituting the coverings are described in more detail below with reference, in particular, to Figures 5 and 6.

[0043] The layers of the pin 100, in the embodiments of Figures 5 and 6, may alternatively constitute the layers of the box 200 and vice versa.

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12/21 [0044] Figure 5 shows an enlarged view of the surfaces of a pin 100 and a box 200, incorporated in a first embodiment of the joint of the invention.

[0045] This configuration, particularly adapted for carbon steel or CRA (corrosion resistant alloys) materials, comprises the following layers:

[0046] a first base metal substrate 1, a pin or, preferably, a box in a bare condition or with the corresponding surface treatment, such as by sandblasting or, preferably, by phosphating for carbon steel or copper electroplating in the case of CRA;

[0047] a second base metal substrate 2, in the box or, preferably, in the pin in a bare condition or with the corresponding surface treatment, such as phosphating or electrodeposition of copper, or, preferably, blasting;

[0048] an optional corrosion protection layer 23 on substrate 2, preferably having a thickness between 10 and 25 pm;

[0049] a high friction factor anti-jam layer on substrate 2, typically with MoS2, graphite and / or boron nitride, etc., having a thickness between 10 and 25 pm;

[0050] a low friction anti-sticking layer on substrate 2, such as fluorinated polymers (for example, polytetrafluoroethylene), between 15 and 40 pm thick; and [0051] an optional corrosion inhibiting layer 26 on substrate 1.

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13/21 [0052] In the joint of the invention, the low friction factor layer 25 is not arranged on surfaces that have axial contact, during the constitution operation.

[0053] The corrosion protection layer 23 can be avoided, in the case where the high friction anti-jam layer 24 also acts as a protective layer.

[0054] In the case of the use of contaminants to reduce friction, located in particular areas, the thickness of the low friction factor 25 anti-jam layer can be negligible. Advantageously, a base layer can be used to ensure adhesion.

[0055] Figure 6 shows an enlarged view of the surfaces of a pin 100 and a box 200, incorporated in a second embodiment of the joint according to the invention.

[0056] In this embodiment, the low friction anti-sticking layer 25, such as fluorinated polymers (e.g. polytetrafluoroethylene), is arranged on substrate 2, as the intermediate layer between substrate 2 of the base metal and the corrosion inhibitor 26 optional.

[0057] The low friction factor 25 sealing layer can also be applied to the opposite element of the threaded joint.

[0058] Also, in this second embodiment, layer 25 is always absent on surfaces having axial contact.

[0059] All these layers, of suitable materials and thickness, in the opposite elements of the threaded joint, increase the radial interference of the joint, but this difference can be compensated advantageously during machining of the joint.

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14/21 [0060] The important factor of their friction, usually the thickness of the coating. Thickness is related to that is, how many co operations to support.

coatings is the coefficient not related in any way, the selection of coating durability, composition and disintegration can [0061] In a particular embodiment, the anti-jam layer 24 can advantageously incorporate corrosion protection, or can be applied to a protective layer.

[0062] In general, protective coatings have overall thicknesses ranging from 10 to 40 qm. If the anti-sealing layer 24 fulfills both the protection and lubricant functions, the overall thickness of the pin and joint housing will be in this range. On the contrary, if the anti-sealing layer and the corrosion protection layer were made of different materials, the overall coating thickness will be greater.

[0063] In some cases, a low friction factor coating is applied to the high friction coefficient coating, as shown in Figure 5. In the case of these pin and case surfaces, which have radial contact with the layer thicknesses, are added, except in the case of axial contact surfaces, only the thickness of the high friction coating is considered to obtain the best results.

[0064] Like the materials contained in the layers, the anti-jam layer 24, having a high friction factor, contains

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15/21 graphite, boron nitride and / or MoS ₂ , as a lubricant, generally using a polymeric resin as a binder (preferably the polymeric resin is an epoxy resin or an ester - epoxy resin), while a low friction factor 25 sealing layer is preferably based on fluorinated polymers (eg polytetrafluoroethylene), or may contain nanoparticles used as a contaminant on radial contact surfaces, which dramatically reduce friction between surfaces without a layer thickness significant.

[0065] The friction coefficients of both layers 24, 25 are different. Typically, the high coefficient of friction coating has a coefficient of friction two or more times that of the low coefficient of friction coating. Typical values for a low friction coating are 0.02 to 0.05, and for a high friction layer it is in the range of 0.05 to 0.12, assessed in a test done with a ring on disk.

[0066] In order to have an excellent relationship between torque, coating thickness and product, generally, the low friction factor layer must be thick enough to cover the entire specific surface during constitution, decreasing the torque, but in addition to a specific limit, an excessive thickness increases the contact pressure, also increasing the necessary torque.

[0067] The rebound torque (S.T.) in a premium joint of the root crest type, is a function of several factors:

S.T. = f (tp, tb, δ, gth, Dh, L) + Ts

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16/21 t _p : medium wall thickness of threaded pin;

t _b : average wall thickness of threaded box;

δ: thread interference;

g _th : 2k on radial contact surfaces;

Dth: average thread diameter;

L: length of coupled thread;

TS: minimal contribution due to sealing interference.

[0068] Still ΔΈ, or torque delta, which is the difference between the plastic flow torque (Y.T.) and the rebound torque (S.T.):

ΔT = f (hn, lth, μsh) hn: shoulder thickness;

lth: thread fillet (tpi); and μsh: friction coefficient on axial contact surfaces.

[0069] Using the high and low friction factors on the axial and radial contact surfaces, respectively (typically, the high coefficient of friction coating has a friction coefficient two or more times higher than that of the low friction coefficient coating. ), it is possible to reduce the ST / YT ratio, which will expand the permissible torque window for a specific joint.

[0070] The graphs in Figure 4 show a comparison between the expected torque - turn graph for the same joint, using a low friction coating (curve A), a high friction coating (curve B) and areas friction points (curve C) according to the invention. The graph shows along the abscissa the number of turns of the joint, to reach a back

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17/21 of the rebounds, and along the ordinate the torque value applied during the constitution.

[0071] The performance of the joint is better when the torque curve has a long segment 50, the value of which is given by the difference between the values of Y.T. and S.T. The higher the value of the segment, the better the security provided by the joint. At

Figure 4, the joint of the invention, which shows a curve corresponding to the curve

C, has a low friction factor on the radial contact surfaces, which provides adequate friction values to guarantee the constitution of the joint at reasonable torque values, comparable to those when using grease; and a high factor in axial contact surfaces, which gives friction gifts a localized area with a high coefficient of friction, capable of transmitting a high resistance to torsion to the joint, once the shoulder comes into contact.

[0072] Other embodiments of the joint according to the invention provide different layers, depending on the pin or box elements in which they are arranged, or, alternatively, contaminating different surfaces on the same coating, to modify their friction factors.

[0073] In another preferred embodiment, layer 24 can also function as a corrosion protector, and the corrosion layer can be avoided.

[0074] To improve the quality of the joint coating, a surface treatment is provided to improve the adhesion of the coating on the thread surface, for example, sandblasting, phosphating or electroplating with copper.

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18/21 [0075] The surface treatment of the invention can be applied to all types of thread, having a cylindrical or truncated shape of the envelope of the thread ridges, or a contamination of both having one or more thread threads.

[0076] The joint of the present invention can be applied to all types of joints, particularly in the case when the female element is formed in a terminal part of a tube, or when a sleeve with two female elements at both ends, to join two male tubes, is used.

EXAMPLE 1 [0077] A coating system was applied to a connection in accordance with the present invention. A first layer of a zinc-rich epoxy resin was applied to the post surface (surface roughness Ra between 2 - 6 qm), as a corrosion inhibiting coating. The final coating thickness was 20 µm. On the first layer, a second layer of dry lubricant coating, which was comprised of a mixture of MoS2 and other solid lubricants in an inorganic binder, was applied with a thickness of 20 qm. The coatings were applied by spraying, and heat was used to accelerate curing.

[0078] The inner surface of the box was coated with a low friction coefficient coating. The surface of a box received a surface treatment of phosphating, and a coating of polytetrafluoroethylene (PTFE) was selectively applied over the crest and the metal - metal seal of the box. This low friction coating was a polymeric coating, which contained PTFE powder dispersed in

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19/21 a reactive epoxy resin and a solvent. The solvents were 2-methoxy-1-methylethyl acetate and xylene. To ensure a homogeneous dispersion of the PTFE powder, the mixture was stirred evenly for 20 minutes. The resin had a viscosity in the range of 26 - 28 seconds in a No. 4 Ford cup at 25 ° C.

[0079] PTFE dispersion was applied to the box by using pneumatic air-free sprinklers. The dispersion was then cured at 140 ° C for 30 minutes. It should be noted that the curing time will vary, depending on the temperature used. For example, epoxy can be cured for 60 minutes at 130 ° C or for 30 minutes at 140 ° C. Alternatively, if the epoxy is cured using an infrared lamp, the recommended curing time is approximately 15 minutes at 140 - 145 ° C.

[0080] The friction coefficient for the polymeric coating of the present example was determined by applying the coating to a flat disk and an annular cylinder (ring). The torque transmitted by rotating the ring on the disk was measured. To simulate the low - pin configuration of the present invention, the pin coatings were applied to the disc, while the box coatings were applied to the ring.

[0081] Figure 7A illustrates the friction coefficient measured over time, while Figure 7B shows the average coefficient. In both Figures 7A and 7B, three different grease-free systems were compared (Solution A, Solution B and Solution C). Solution A devoid of grease had a coating system comprised of a corrosion resistant layer and a lubricating layer on the pin. Solution B without grease

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20/21 had the same coating system as solution A, but a corrosion inhibiting layer was applied to the top. The grease-free solution C, the solution of the present example, had the coating scheme of solution B applied to the pin and a PTFE coating was applied to specific parts of the inner surface of the box.

[0082] It can be noted that in Figures 7A and 7B the polymeric coating significantly reduced the friction coefficient, when applied in accordance with the present invention, especially compared to conventional pin-box configurations.

[0083] In addition to the friction coefficient tests, constitution and disaggregation tests were conducted on connections of 8.9 centimeters (3.5 inches). The results of these tests are shown in Figure 8. In Figure 8, the solutions without grease A, B and C were evaluated in the connections with two different configurations; max. interferences thread / max. seal and min. thread / max. seal. In Figure 8, the main bars represent the average rebound torque for the first 5 constitutions for each of the configurations, the points symbolize the torque rebound for the first constitution, and the error bars indicate the standard deviation. In the legend, HHN means high thread interference - high seal interference with nominal thread narrowing, while LHN means low rose interference - high seal interference with nominal thread narrowing. As can be seen in Figure 8, the application of the PTFE coating has considerably reduced the torque rebound.

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[0084] It should be noted that other types of polymeric coatings can be used in addition to the PTFE coating of Example 1, and that Example 1 is not intended to limit the scope of the present invention. As those skilled in the art will understand, other coatings can be applied below or above the polymeric coating, without departing from the scope of the present invention. For example, a corrosion resistant layer can be applied over the polymeric coating, as long as the corrosion resistant layer does not affect the friction properties of the entire system. In addition, the various coatings described here can be applied to the entire surface of the pin element or box element, or only to selected areas. For example, coatings can be applied to the threaded parts of the pin element and the box element, to the metal - metal seal parts of the pin element and the box element, or to the raised part of the pin element and the box element, without moving away the scope of the present invention.

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Claims (17)

1. Threaded joint for tubes comprising pin (100) and box (200) elements, the pin element (100) having a thread adapted to fit a thread of the box element (200), a thread shape of each of the pin elements (100) and the box element (200) defined by a thread profile, which extends in a cross section containing a longitudinal axis (X) of the joint, in which the surface of the pin element (100) is provided with a coating comprising a first layer (12, 12 ', 24) with high friction properties disposed on the global surface of the pin element (100), a second layer (13, 13', 25) with friction properties lower than the properties of friction of the first layer characterized by the fact that said first layer has anti-sealing properties and said second layer is placed only on the first portions of the global surfaces of the pin (100) or box (200) elements, in which the first portions are parts of the surface that produces Use reciprocal radial contact between pin and housing during assembly until a supporting surface supporting an axial contact pressure load is supported. 2. Threaded joint for tubes comprising pin (100) and box (200) elements, the pin element (100) having a thread adapted to fit a thread of the box element (200), a thread form of each of the pin elements (100) and the box element (200) defined by a thread profile, which extends in a cross section containing a longitudinal axis (X) of the joint, in which the surface of the box element is provided with a coating comprising a first layer (12, Petition 870190009139, of 28/01/2019, p. 25/45 2/4 12 ', 24) with frictional properties arranged on the global surface of the box element (200), a second layer properties in fact that anti-sticking properties in the frictional properties of the first to said first frictional properties lower than the layer characterized by the layer has property and said second layer is arranged only by parts between imeiras portions of surfaces global elements 100) or Cashier ( 200) , on what at first portions are from the surface what produce radial contact reciprocal the pin and the box during The assembly up that one support bearing an axial surface contact pressure load is supported. Threaded joint according to claim 1 or 2, characterized in that the first portions are crests in the box element, roots in the pin element and metal - metal seals. 4. Threaded pipe joint according to claim 1 or 2, characterized in that the surface undergoing an axial contact pressure load is a shoulder (9, 10). Gasket according to any one of claims 1 to 4, characterized in that a layer (26) incorporating corrosion inhibiting material is also applied to the pin or housing. Petition 870190009139, of 28/01/2019, p. 26/45 3/4 6. Gasket according to any one of claims 1 to 4, characterized in that the first layer (24) incorporates a corrosion inhibiting material. Gasket according to any one of claims 1 to 4, characterized in that a protective layer of corrosion (23) is applied before the first layer (24). 8. Gasket according to any one of claims 1 to 4 characterized by the fact that the first layer (24) incorporates MoS2, graphite and / or boron nitride, and has a thickness in a range between 10 and 25 gm. Joint according to any one of claims 1 to 4, characterized in that the first layer also contains an organic or inorganic polymeric resin as a binder. Gasket according to claim 9, characterized by the fact that the polymeric resin is an epoxy resin or an ester - epoxy resin, or an inorganic binder capable of being polymerized and crosslinked. Gasket according to claim 1 or 2, characterized in that the first layer of the coating comprises a layer (23) which incorporates a corrosion inhibiting material having a thickness between 10 and 25 gm. 12. Joint according to any one of claims 1 to 4 characterized by the fact that the pin or the box is in a Petition 870190009139, of 28/01/2019, p. 27/45 4/4 bare condition or have a surface treatment selected from sandblasting, phosphating or copper electrodeposition. Gasket according to any one of claims 1 to 4, characterized in that the second layer (25) contains fluorinated polymers and has a thickness in the range between 15 and 40 qm. Gasket according to claim 1 or 2, characterized in that the second layer (25) contains nanoparticles. Joint according to claim 1 or 2, characterized by the fact that the high friction coating has a friction coefficient two or more times higher than that of the low friction coating, and the values for the friction coefficient of a coating low friction are from 0.02 to 0.05, and for the high friction layer they are in the range of 0.05 to 0.12. 16. Joint according to any one of claims 1 to 4, characterized in that the joint has a cylindrical or truncated shape of the envelope of the thread ridges, or a combination of both. 17. Gasket according to any one of claims 1 to 4, characterized in that the female element is formed at one end portion of a tube or when a sleeve with two female elements at both ends, to join two male tubes, is used.